Heck, Donald

Introduction: Outcomes from endovascular procedures are highly dependent on the experience and skill of the operating physician. The multi-disciplinary CREST-2 Interventional Management Committee (IMC) was charged with credentialing a cohort of skilled interventionists with adequate contemporary case volumes. Methods: Applicants were required to submit 25 consecutive cases completed within 5 years as primary operator out of a required total experience of ≥ 50 cases (≥ 20 for operators completing training). Interventionists not approved on initial review were asked to submit additional cases (with procedural angiograms), the number depending on quality and recent-quantity of the cases. Results: The IMC has had 102 meetings, and 283 interventionists have been evaluated: 104 (37%) interventionists were cardiologists, 64 (23%) vascular surgeons, 42 (15%) neurosurgeons, 32 (11%) neuroradiologists, 26 (9%) neurologists, 9 (3%) interventional radiologists, and 6 (2%) other. The mean total experience among the 226 interventionists with available information was 220±263 carotid stent cases (median 135; range 10-2500). A total of 7037 cases have been reviewed by the IMC, dating from August 2001 to April 2016, with 3366 symptomatic, 3541 asymptomatic and 130 undetermined. The range of cases reviewed per interventionist was 5 to 50. Of the 251 interventionists with sufficient periprocedural follow-up data, no stroke events were reported by 152 (60.5%), and at least one or more stroke events were reported by 99 (39.5%). The IMC has approved 115 interventionists, 29 at the first review and 86 subsequently, based upon submission and review of 631 additional contemporary cases (mean=7 cases per interventionist); 122 have approval pending submission of additional cases; 33 have been denied; 8 have been deferred; 4 have been approved for the CREST-2 Companion Registry only; and 1 is pending decision. Discussion: Rigorous evaluation and credentialing of carotid stenters in CREST-2 has been demanding, for the candidates and for the evaluators. Yet the cohort of interventionists so selected should be able to provide the high-quality stenting outcomes necessary for acceptance of the trial results.

Background and Purpose: The CREST2 trial (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis) is comparing intensive medical management (IMM) alone to IMM plus revascularization with carotid endarterectomy or transfemoral carotid artery stenting for preventing stroke or death within 44 days after randomization or ipsilateral ischemic stroke thereafter. There are extensive clinical trial data on outcomes after revascularization of asymptomatic carotid stenosis, but not for IMM. As such, the experimental treatment in CREST2 is IMM, which is described in this article. Methods: IMM consists of aspirin 325 mg/day and intensive risk factor management, primarily targeting systolic blood pressure <130 mm Hg (initially systolic blood pressure <140 mm Hg) and LDL (low-density lipoprotein) cholesterol <70 mg/dL. Secondary risk factor targets focus on tobacco smoking, non-HDL (high-density lipoprotein), HbA1c (hemoglobin A1c), physical activity, and weight. Risk factor management is performed by site personnel and a lifestyle coaching program delivered by telephone. We report interim risk factor data on 1618 patients at baseline and last follow-up through 24 months. Results: The mean baseline LDL of 80.5 mg/dL improved to 66.7 mg/dL. The mean baseline systolic blood pressure of 139.7 mm Hg improved to 130.3 mm Hg. The proportion of patients in-target improved from 43% to 61% for systolic blood pressure <130 mm Hg and from 45% to 67% for LDL<70 mg/dL (both changes P <0.001). Conclusions: The rigorous multimodal approach to intensive stroke risk factor management in CREST2 has resulted in significant improvements in risk factor control that will enable a comparison of cutting-edge medical care to revascularization in patients with asymptomatic carotid stenosis. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02089217.

Rationale: Asymptomatic carotid stenosis is commonly seen in medical practice. CREST-2 is a pair of concurrent two-arm multi-site randomized trials of intensive medical management versus intensive medical management in combination with revascularization by endarterectomy or stenting. It is not known how often patients entering the trials have opportunities for further risk factor reduction at study entry and whether these opportunities vary across trial centers. Methods: Baseline data on 683 patients from 109 clinical sites were used for these analyses. We determined the rates of control at baseline for systolic blood pressure (SBP), defined as <140 mmHg (or ≥140 with >15mmHg orthostatic drop), and low density lipoprotein (LDL), defined as <70 mg/dl. We then tested differences in these baseline control rates by site-related characteristics, including site type, StrokeNet site vs. not, specialty of site Principal Investigator (PI), type of hospital, central vs local IRB, type of research team and whether site is enrolling in one or both trials. P-value <0.05 was considered significant. Results: At baseline, the mean SBP was 140.4±20.5 mmHg, but only 62% of participants were in target. The mean LDL at baseline was 83.7±36.9, mg/dl, with 42% in target. None of the site characteristics were associated with a higher level of control for SBP at baseline. The only characteristic associated with having a higher level of LDL control was sites enrolling in only the CAS trial (57%) compared to those enrolling in the CEA only (24%) or in both trials (42%) (p=0.02). Conclusions: Opportunities to improve on risk factors are common among CREST-2 participants, but site characteristics did not predict the likelihood of being at goal for SBP while sites enrolling in only the CAS trial had a higher level of LDL control.